Enable Terraform to provision locally for the voting-app sandbox app (per #15)

[danielcbright]

Make this:

module "sandbox-apps" {
  resource_name = "voting-app"
  source = "../_terraform/"
  # resource_size = "t2.micro" # only change for unusually large/small projects. bigger == $$$
}

look like this:

module "sandbox-apps" {
  resource_name = "voting-app"
  source = "../_terraform/"
  location = "local" #or "aws"
  # resource_size = "t2.micro" # only change for unusually large/small projects. bigger == $$$
}